Method of coating wire



July 22,'1930 c. D. JOHN-SON 1,771,379 METHOD or coulis una:

^ Filex may s1, 1929 lnvenor.

` Chad DJohnson bymwym AHys.

Patented July 22, `1930 I UNITED. STATI-:s-

PATE/Nr oFFlcr;

CHARLES D. JOHNSON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO JOHNSON STEEL da WIRE CO. INC., OF WORCESTER, MASSACHUSETTS, A CORPORATION Ol* MASSACHU- SETTE METHODV F COATING WIRE Application 'led Hay 31,

This invention relates to the coating of wire and especially to the application of a coating of copper to Wire. One Well-known Way to coat wire with copper is to pass the wire through a bath of aqueous salt solution such q as blue vitriol or a similar' coating material.

In thus coating the wire it is advantageous to keep the coating bath Well agitated so as to maintain it of a uniform consistency. I have discovered that the coating of copper which is deposited on the wire will be heavier and `will be applied more evenly when the coating l which is applied to the wire Will be heavier and Will be more evenly applied When the coating apparatus is started up on a cool day than it will be later in the day, since when the machine is started up the bath Will be at the low temperature it has acquired during the night While as the day Wears on the temperature of the bath naturally rises.

It is one of the objects of my invention to provide a novel method of and apparatus for coating the Wire by which the means for agitating the bath and keeping it thoroughly stirred `may be used to maintain the desired low temperature in the bath.

The coating bath is kept agitated by intro- 1 ducing airinto it, the air bubbling up through the Iliquid bath and thus keeping it thoroughly stirred and mixed. In order to provide for maintaining the desired temperature in the bath I propose to cool the air which is admitted to the bath so that the air which agitates the bath Will serve also to cool the bath and keep it at the desired cold temperature. This may conveniently be done 'by providing a cooling chamber which has in it some cooling unit and then by blowing air through the chamber and into the bath, the air becoming sufficiently cool while passing through the chamber to perform the desired function of keeping the bath cool. Another feature of the invention relates to a novel manner of treating the coated Wire after it leaves the aqueous 1929. Serial No. 387,184.

coating bath by which it is thoroughly dried and at the same time polished before itis eX- posed to the atmosphere forany appreciable length of time. The advantage resulting from this is that the drying can be accomplished with no appreciable oxidization of the wire.

According to thisfeature of the invention the coated wire as it comes from the washingV bath 1s first sub]ected to the action of wipers sand or gravel thoroughly dry and in a polished condition.

In order to give an understanding of the invention I have illustrated in the drawings a selected embodiment thereof which will now be described after whichvthe novel features will be pointed out in the appended claims.

Inthe drawings, Fig. 1 is a diagrammatic vlew illustrating a coating apparatus em-f bodying my invention Fig. 2 is a plan View of the coating bath and the cooling apparatus therefor.

Y The actual coating of the Wire is performed in usual Way by passing it through a bath of aqueousl coating material, such as blue vitriol if the wire is to be coated with copper.

As shown in the drawings the wire to be coated is indicated at l and the coating bath is shown at 2, it beingv contained in a suitable container 3. The wire is shown as being drawn from a spool 4 and as passing through an acid bath 5 and thence through a washing bath 6 in which it is Washed and thence chamber to the temperature of 70 F. or 80 F.

ture remaining on the bath 2 has located in it a coil of pipe 9 which is provided with numerous perforations, so that air which is forced into the pipe 9 will escape through the perforations and bubble up through the bath 2 thus keeping it thoroughly agitated. l The pipe 9 leads to a cooling chamber 10 which is provided with means for cooling the air therein and said chamber is connected by a pipe 11 with a blower or air-forcing mechanism 12.

Any suitable means may be employed in the cooling chamber 10 for cooling the air there- 1n. have herein shown at 13 a cooling unit which may be any ot the well known p electrically-actuated units of the type used in electric refrigerators or may be any suitable cooling unit.

In the operation of the device the-blower 12 `blows air into and through the cooling chamber 10, the airpassing from the cooling pipe 9 from which it is delivered into the coating bath. The size of the cooling chamber 10 and the size of the cooling unit 13 will besuch that the air which is delivered from the cooling chamber will be at a relative] low temperature. The air bubbling up t rough the bath 2 will keep itv thoroughly agitated and by having the air delivered to the bath at the proper low temperature, the temperature of the .aqueous coating solution will Vbe keptat the proper sub-normal point to ensure the deposit on the wire of an even coating of uniform thickness. v

With my apparatus it is possible tomaintain the bath-2 at a substantially uniform temperature regardless of weather conditions and thus it is possible-to apply to the wire an even coating throughout the day and regardless of changes of temperature in the room. Moreover, I find that'the coating which is applied when the bath is tively low temperature adheres to thev wire better and is less likely to flake off than 'a coating which is applied when the bath is-at a After the coated wire leaves the coating bath 2 and passes through a washing bath 7 of water by which it is cleaned and as itjlcaves the Washing bath 7 the .surplus4 Water is removed therefrom by some suitable means such as the wipers 14. The wire is thenV im-` mediately passed through a bed 8 of highly heated granular material such as sand or gravel. The high temperature of the sand or gravel quickly evaporates any water or moiscoated wire after passing through the wipers and as this drying is done while the wire is embedded in the granular material there will be no appreciable oxidization of the wire as it is dried such as might occur ifthe wire were dried va washing bath it imme iately at a relain the open airV gravel. Moreover, the granular material will have a polishing or cleaning effect on the coated wire so that as it leaves heated bed 7 of sand or gravel it will not only be thoroughly dried but will also be more or less polished.

The bed8 of sand or in any suitable way. As herein shown it 1s located on. the top of a heating chamber 15 which may be heated by any suitable means such as a burner tube 16 for burning oil'or gas. With this arrangement the sand 8 can be kept at a relatively high temperature necessary for quickly drying the wire.

I claim:

1. TheV method of making metal-coated y wire which consists in pasing uncoated wire throu h an aqueous metal-coating bath Where y it is coated, then passing it through whereby'it is cleaned, then removin surplus water from it and passing ed granular material by` which said metal- Coated iwire is both thoroughly Kdried and p olished prior to substantial contact with the air.

2. The` method of making metalcoated wire which consists in passing the Vwire throughan acid bath for cleaning it and thence through a water bath for washing it and thence through anaqueous metal-coating bath whereby it is metal coated, then passing the wire through a washing `bath whereby it is cleaned, removing thesurplus water from the wire as it'leaves the washing bath and immediately passing the wire througha mass of hi hly heated inert granular material whereby the coated wire is dried while buried in the heated granular material and before it is exposed to the atmosphere for any appreciable length of time.

.y 3. The method 2of-making metal-coated wire which consists in Ilpassing the wire through an equeous metal coating bath whereby it is metal coated, keeping the bath at a uniform low temperature and simultaneously agitating the bath by introducing into the bath cooled air which bubbles up therethrough whereby a coat of substantially even thickness will be applied to the wire.. In testimony whereof, I have signed my name to this specification.

CHARLES D; JOHNSON.

because of the fact that the Wire is protected,v from contact with the air by the sand or" through a mass of highly heatthe highly 

